There are many options.
The easy safe solution is to,
A) Remove existing HDD & connect SSD instead.
B) Install a fresh copy of Windows on SSD from DVD.
C) Reconnect HDD
D) Change the disk boot order in BIOS to make SSD 1st boot drive
E) Copy across any files you need from HDD and re-install apps you need.
F) Remove and keep old HHD as backup, and don't reformat it.
Other options include imaging HDD drive and copying image to SSD. But you can run into problems if SSD is smaller than HDD (as they often are).